Floor systems are the horizontal supporting surfaces of a building structure. Such floor systems not only support the contents of a building but also carry the weight of their own constituent parts and any extra load from floors and walls above. To avoid collapse, a floor system must readily transfer these loads laterally to beams, columns or bearing walls with a satisfactory margin of safety.
In residential construction, the conventional floor system is assembled from a plurality of horizontal, wooden beams or joists overlaid with a plane of sheathing material. Depending upon the strength of the materials utilized, the depth of such a floor system may be varied somewhat and still meet accepted standards for safety. Of course, potential holes or cavities within the floor system must also be considered in determining the proper depth of a floor system if it is necessary to accommodate heating, plumbing, or electrical conduits.
Utility conduits normally run parallel to joists in floor systems. Under certain conditions, however, these conduits may run perpendicular to, and penetrate, the joists. Local building codes have strictly mandated that a transverse hole bored or cut into a joist for accommodating a conduit shall not be closer than 2 inches to the top or bottom of the joist. Further, the diameter of the hole shall not exceed one-third of depth of the joist. Limits have also been placed upon the distance from the end of the joist where a transverse hole can be located.
Holes for plumbing drain conduits, with their relatively large diameters, are particularly difficult to position in the wooden joists typically used in residential building structures. A conventional plumbing drain conduit having an outside diameter of 31/4 inches, for instance, cannot in many areas be lawfully passed through a 2.times.10 joist having actual dimensions of 15/8 inches by 91/4 inches. The 35/8 inch hole needed to accommodate the 3 1/4 inch diameter conduit fails to satisfy the building code requirement that the hole not exceed one-third of depth of the joist. Thus, residential builders have had to utilize joists having larger nominal dimensions of 2 inches by 12 inches which are more expensive and somewhat heavier in weight. A need, therefore, exists for a bracket which can act as a "patch kit" to reinforce a wooden joist having a transverse hole to such an extent that it is equal in load-bearing capacity to that of a similarly dimensioned joist that lacks any transverse holes.